Inhalant Anesthesia Flashcards
What are the cons of inhalant anesthesia?
- Specialized (expensive) equipment needed
2. Equipment can fail (need monitoring and expertise)
T/F. The dosage for inhalant anesthetic drugs is expressed as a concentration (VOLUME %) of the whole gas mixture. Can be discussed as INSPIRED FRACTION (FI) of the drug.
True
Most inhalant anesthetics are VAPORS. What does a vapor refer to?
Gaseous state of a substance that at ambient temperature and pressure is a liquid.
T/F. Because the vapor pressure for different drugs varies, the vaporizer does not have to be matched to the specific drug.
False.
The vaporizer HAS to be matched to the specific drug.
Which of the following is INCORRECT about solubility of inhalant anesthesia?
A. Blood/Gas solubility coefficient is the most clinically relevant measure of solubility.
B. The more soluble the anesthetic agent, the shorter it will take to reach equilibrium.
C. A more soluble drug will want to get in the blood and spend more time in the blood (the blood is acting like a sponge that is soaking up the anesthetic drug.
D. The more insoluble the agent, the faster it will reach equilibrium.
B. The more soluble the anesthetic agent, the shorter it will take to reach equilibrium.
The more soluble the anesthetic agent (higher blood/gas coefficient), the LONGER it will take to reach equilibrium (slower induction, recovery, and response to changes in dose).
T/F. Halothane has a blood/gas coefficient of 2.4. This means that the concentration of halothane dissolved in the blood will be 2.4 times less than the concentration in gas form (in the alveolus) at equilibrium.
False.
2.4 times GREATER than the concentration in gas form at equilibrium.
T/F. Desflurane has a blood/gas coefficient of 0.45 so at equilibrium, the concentration dissolved in blood will only be 0.45 times that in the alveolus.
True
Why would a more insoluble drug in blood will rise and fall rapidly compared to a more soluble drug?
A. The premise is false; a more insoluble drug in blood will NOT rise and fall more rapidly.
B. A more insoluble drug will more readily move into blood and less readily leave the blood.
C. A more insoluble drug will less readily move into blood and more readily leave the blood.
C. A more insoluble drug will less readily move into blood and more readily leave the blood.
What would happen if an anesthetic drug is completely insoluble?
It would never enter the bloodstream/tissues ad thus be USELESS!
What does MAC stand for? What is it?
Minimum Alveolar Concentration.
The equilibrium concentration of an anesthetic in the alveolus that is required to prevent movement and response to pain 50% of individuals (similar to an anesthetic ED50).
Which of the following statement regarding MAC is FALSE?
A. Vary between different drugs and between different species for the same drug.
B. If 1.3MAC is needed for anesthetic maintenance and a particular inhalant is 1.5%, you would set your vaporizer to 2%.
C. Required amount of inhalant will change based on the patient’s physiologic status or the presence of other drugs.
D. None of the above.
E. All of the above.
D. None of the above
What are the pros of inhalant anesthetic drugs?
- Control of the airway and ventilation
2. Control over drug uptake and elimination
T/F. The pharmacokinetics of inhalant anesthetic is very different than most drugs because it occurs primarily via the lungs.
True.
Which of the following is INCORRECT about ABSORPTION relating to inhalant anesthetics pharmacokinetics?
A. Absorption happens completely through the lungs at the level of the alveolus.
B. Gas needs to reach the alveoli > diffuse across the alveolus into capillaries.
C. Gas concentration in the alveoli = Gas concentration in the bloodstream.
D. If there is a disease in the lung, normal diffusion will be increased.
E. If the lung perfusion is reduced (decreased CO), absorption will be impaired.
D. If there is a disease in the lung, normal diffusion will be increased.
If there is a disease in the lung, normal diffusion will be decreased (not as effective).
Which of the following statement is INCORRECT about DISTRIBUTION relating to Inhalant anesthetic pharmacokinetics?
A. Distribution is generally good for anesthetic agents (all lipid soluble to cross BBB).
B. We expect to have a reduction phase (higher rates of inhalant are needed until the tissue reservoirs have filled and equilibrium is reached).
C. After a few minutes of delivery, it can be turned down to maintain blood and tissue (brain) levels (maintenance phase).
D. Inhalant anesthetics will cross the placenta.
B. We expect to have a reduction phase (higher rates of inhalant are needed until the tissue reservoirs have filled and equilibrium is reached).
AN INDUCTION PHASE > can be turned down to maintenance phase.